1. Technical Field
The present invention concerns a ship, in particular a cargo ship, having a Magnus rotor
2. Description of the Related Art
Magnus rotors are also referred to as Flettner rotors or sailing rotors.
The Magnus effect describes the occurrence of a transverse force, that is to say perpendicularly to the axis and to the afflux flow direction, in relation to a cylinder which rotates about its axis and which has an afflux flow perpendicularly to the axis. The flow around the rotating cylinder can be interpreted as a superimposition of a homogenous flow and an eddy around the body. The irregular distribution of the overall flow results in an asymmetrical distribution of pressure at the periphery of the cylinder. A ship is thus provided with rotating or turning rotors which in the wind flow produce a force which is perpendicular to the effective wind direction, that is to say a wind direction that is corrected with the highest speed, which force can be used similarly as when sailing to propel the ship. The cylinders which stand upright rotate about their axis and air which flows in an afflux flow thereto from the side then preferably flows in the direction of rotation around the cylinder by virtue of surface friction. Therefore on the front side the flow speed is greater and the static pressure is lower so that a force in a forward direction is imparted to the ship.
Such a ship is already known from “Die Segelmaschine” by Claus Dieter Wagner, Ernst Kabel Verlag GmbH, Hamburg, 1991, page 156. That involved investigating whether a Magnus rotor, also referred to as a Flettner rotor, can be used as a drive or auxiliary drive for a cargo ship.
U.S. Pat. No. 4,602,584 discloses a drive system for a ship, having a conventional screw and rudder arrangement with one or more rotor sails. In that case production of the propulsion is effected by way of a conventional drive machine controlled by a conventional control system and utilization of the Magnus effect by the rotor sails. The conventional drive machine can drive the rotor sails which as will be noted however can also be driven by their own drive. The rotor sails are controlled by a control unit provided on the bridge and having two levers by way of which the rotary speed and direction of rotation of the rotor sails can be set in order thereby to influence the direction of the propulsion force produced by the Magnus effect.
DE 10 2005 028 447 A1 discloses a ship having a plurality of Magnus rotors, wherein an individually actuable electric motor is associated with each of the plurality of Magnus rotors for rotating the rotors. Associated with each electric motor is a converter for controlling the rotary speed and/or the direction of rotation of the electric motor.